<!DOCTYPE html>
<html>
<head>
<title>计算器</title>
<meta charset="UTF-8">
<style>
body {
background-color: #f2f2f2;
font-family: Arial, sans-serif;
}
.container {
width: 300px;
margin: 0 auto;
padding: 20px;
background-color: #fff;
box-shadow: 0 0 10px rgba(0,0,0,0.2);
border-radius: 5px;
}
input[type="button"] {
width: 50px;
height: 50px;
background-color: #ccc;
border: none;
border-radius: 5px;
font-size: 24px;
cursor: pointer;
margin: 5px;
}
input[type="text"] {
width: 100%;
height: 50px;
font-size: 24px;
padding: 5px;
margin-bottom: 10px;
box-sizing: border-box;
}
</style>
</head>
<body>
<div class="container">
<input type="text" id="result" readonly>
<input type="button" value="1" onclick="addToResult(1)">
<input type="button" value="2" onclick="addToResult(2)">
<input type="button" value="3" onclick="addToResult(3)">
<input type="button" value="+" onclick="addToResult('+')">
<br>
<input type="button" value="4" onclick="addToResult(4)">
<input type="button" value="5" onclick="addToResult(5)">
<input type="button" value="6" onclick="addToResult(6)">
<input type="button" value="-" onclick="addToResult('-')">
<br>
<input type="button" value="7" onclick="addToResult(7)">
<input type="button" value="8" onclick="addToResult(8)">
<input type="button" value="9" onclick="addToResult(9)">
<input type="button" value="*" onclick="addToResult('*')">
<br>
<input type="button" value="0" onclick="addToResult(0)">
<input type="button" value="." onclick="addToResult('.')">
<input type="button" value="C" onclick="clearResult()">
<input type="button" value="/" onclick="addToResult('/')">
<br>
<input type="button" value="=" onclick="calculate()">
</div>
<script>
function addToResult(value) {
document.getElementById("result").value += value;
}

function clearResult() {
document.getElementById("result").value = "";
}

function calculate() {
var result = eval(document.getElementById("result").value);
document.getElementById("result").value = result;
}
</script>
</body>
</html>
